A display panel, a display device and a signal transmission device are provided. The display panel includes: an array substrate; an opposed substrate arranged opposite to the array substrate; a circuit board, disposed on a side of the array substrate away from the opposed substrate; a driving circuit, disposed on a side of the array substrate close to the opposed substrate; a light emitter, disposed on a side of the circuit board close to the array substrate and electrically connected with the circuit board, in which the light emitter includes a light emitting surface which faces the array substrate; and a light receiver, disposed on a side of the array substrate close to the opposed substrate and electrically connected with the driving circuit, in which the light receiver includes a light receiving surface which faces the light emitter.